UPLC-MS Determination of Residual Amounts of 14 Fluoroquinolone Antibiotics in Drinking Water

UPLC-MS was applied to the determination of residual amounts of 14 fluoroquinolone antibiotics in drinking water. The sample was passed through Oasis HLB (200 mg/6 mL) SPE column to enrich the fluoroquinolone antibiotics which were eluted from the SPE column with methanol. The eluate was then separated by using Acquity UPLC BEH C18 chromatographic column as stationary phase, and mixtures of (φ) 0.1% formic acid solution and (φ) 0.1% formic acid-acetonitrile solution (mixed in various ratios) as mobile phase in gradient elution. ESI+ was adopted in MS. Linear relationships between values of peak area and mass concentration of the 14 fluoroquinolone antibiotics were kept in definite ranges. Detection limits (3S/N) found were ranged from 0.04 to 1.8 ng·L-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 69.2%-85.2%, with RSD′s (n=6) in the range of 4.5%-11%.